Clappia umbilicata

Umbilicate pebblesnail
Drawing of apertural view of the shell and its operculum of Clappia umbilicata
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
(unranked): clade Caenogastropoda

clade Hypsogastropoda
clade Littorinimorpha
Superfamily: Rissooidea
Family: Lithoglyphidae
Genus: Clappia
Species: †C. umbilicata
Binomial name
Clappia umbilicata
(Walker, 1904)[2]
Synonyms[1][4]
  • Somatogyrus umbilicatus Walker, 1904
  • Lithoglyphus umbilicata Walker, 1904
  • Clappia clappi Walker, 1909[3]

The umbilicate pebblesnail, scientific name Clappia umbilicata, is an extinct species of a small freshwater snails that had an operculum, aquatic gastropod mollusks in the family Lithoglyphidae.[5]

Contents

Distribution

This species was endemic to the Alabama, United States.[1] The type locality is Coosa River at Wetumpka, Alabama.[2]

Its distribution included: Coosa River at Duncan's Ripple, The Bar and Higgin's Ferry in Chilton County; and Butting Ram Shoals in Coosa County, Alabama.[3][6]

Description

This species has been discovered and described under the name Somatogyrus umbilicatus by American malacologist Bryant Walker in 1904.[2] Walker's type description reads as follows:

“

Somatogyrus umbilicatus n. sp. Pl. v, fig. 5.

Shell small, globosely depressed, umbilicate, light greenish-yellow, smooth, except for the fine, rather unequal, lines of growth. Spire short, obtusely elevated. Whorls 3½ those of the spire convex and separated by a well-impressed suture; body whorl large, gibbously convex. Aperture sub-circular, rather longer than broad, obtusely angled above and slightly flattened along the basal margin. Columella concave, narrowly reflected; columellar callus, moderately heavy, rounded, reflected over but not concealing the round, deep umbilicus, thin and transparent on the parietal wall. Alt. 3, diam. 3 mm.

Coosa river at Wetumpka, Ala. (type locality), also at Fort Williams Shoals above Farmer, Ala.

This species is remarkable for its depressed, valvata-like form and round, deep umbilicus, which readily differentiates it from all other known species of the genus. It does not appear to be very abundant at AVetumpka, and only a single example was collected at Fort Williams Shoals.

 ”

The color of Clappia umbilicata was black.[3] It presumably mean the whole animal including snout, nape, mantle and foot.[5] The black color of the mantle has been verified by Thompson (1984).[5]

Clappia umbilicata has 56-59 rows of teeth on its radula.[5] Each row has 6-7 central basocones, 6-7 central octocones, 18-21 lateral teeth, ca. 50 inner marginal teeth and ca. 35 outer marginal teeth.[5]

Ecology

Its natural habitat was rivers.[1] Clappia umbilicata required rapid flowing sections of river shoals.[5] It died out because of silting of its habitat after the dam was constructed[1] (Jordan Dam and Jordan Lake).

Based on examination of radula, Thompson (1984)[5] hypothesized, that Clappia umbilicata was grazing on fine particles of plants and it was specialized on more fine partiecles than the genus Somatogyrus.[5]

References

This article incorporates public domain text from reference[2][6]

  1. ^ a b c d e Mollusc Specialist Group (2000). Clappia umbilicata. 2006 IUCN Red List of Threatened Species. Downloaded on 6 August 2007.
  2. ^ a b c d Walker B. (1904). "New species of Somatogyrus". The Nautilus 17(12): 133-142. page 137. plate 5, figure 5.
  3. ^ a b c Walker B. (1909). "New Amnicolidae from Alabama". The Nautilus 22(9): 85-90. page 89.
  4. ^ Kabat A. R. & Hershler R. (1993). "The prosobranch snail family Hydrobiidae (Gastropoda: Rissooidea): review of classification and supraspecific taxa". Smithsonian Contributions to Zoology 547: 1-94. page 18. PDF.
  5. ^ a b c d e f g h Thompson F. G. (1984). "North American freshwater snail genera of the hydrobiid subfamily Lithoglyphinae". Malacologia 25(1): 109-141.
  6. ^ a b Clench W. J. (1965). "A new species of Clappia from Alabama". The Nautilus 79(1): 33-34. Figure 2.